This invention relates to improvement to an existing manual metal stock bender to additionally provide the ability to twist square or flat metal stock.
A metal stock bender using manual power is available which provides a means of bending stock metal of various shapes around a die in the horizontal plane to produce a shape conforming to the exterior of the die. A twisted shape can not be produced using this bender, or any other bender, because only one revolution can be made around the centered die required to provide the desired bend shape. Since the manual stock bender requires a sturdy pedestal to provide horizontal bending around a die which takes up a considerable amount of room, it would be desirable if the apparatus attached to the pedestal could be adapted to alternately attach either the bender apparatus or twister apparatus. Adding a twister function would minimize shop space at a minimum cost for these two functions.
U.S. Pat. No. 5,626,045 is hereby incorporated by reference. The instant invention provides an improvement for this invention, which provided a metal bending function. The instant invention substitutes adaptor apparatus for the previous apparatus attached to the top of the pedestal and includes twister apparatus, being arranged such that either metal bending or metal twister operations can be provided by this one apparatus.
Adapting the above bender to also provide the twister function, not only includes adding twister elements, but also requires that the bender and twister functions do not interfere with one another. When twisting metal stock this is accomplished here by providing the twister parts and removing those bender parts which would interfere with the twisting operation, and alternately when bending metal this is accomplished by removing all of the twister parts while providing all of the bender parts. This eliminates any possibility of interference between the parts used for bending with those used for twisting. These changes must be both easy and rapid for this dual use to be acceptable to a user. This goal is accomplished as described below.
The adaptor apparatus primarily consists of an upper and a lower vertically stacked adaptor plate. These plates are spaced apart by cylindrical shaped spacers and attached to a top plate which is welded to the pedestal. These adaptor plates provide essentially the same forming die holder arrangement as before, including the plates having aligned extensions with multiple pairs of aligned holes to pivotably secure various sized dies which was provided by the U-shaped forming die holder before. The lower plate also has a circular shape, with a number of stop holes about the periphery encircling the die holder as before. The end opposite to the adaptor plates is arranged to secure the slide bar in the same attitude with respect to the other parts of the bender apparatus as before. The adaptor plates also provide the same attachment locations and multiple holes for the bending apparatus as before.
A vertical cylinder, offset from the pedestal, is attached through the plates to provide a vertical twister pivot hole. The bender apparatus does not utilize this twister pivot hole. This arrangement, with the cylinder located within the plates, ensures that the cylinder does not interfere with the bender operation. All of the movable bending parts are attached to the adaptor apparatus or to each other are attached by removable pins as before. The slide bar of the bender apparatus, which is fixed in position, extends into a slot in the cylinder and is attached through holes in the opposed adaptor plates by a single bolt. The bolt also extends through centering bushings mounted on opposite sides of the bar.
The above arrangements provide for quick attachment and removal of the bender parts which could interfere with a twisting operation.
The twister parts include only a twister lever, a clamp and a bottom locator. The twister lever has a perpendicular extension from one end of made up of an inner and an outer cylindrical shaped portions. The inner portion is solid with a centered hole arranged to grip the cross-section of stock which extends through the hole. The outer portion is coaxial with the inner portion and in the form of a cylindrical shaped shell. The outer portion is larger than the hole through the inner portion but smaller than the inner portion which provides a ledge between the inner and the outer portion. The outer portion is sized to mate with the cylinder through the adaptor. This provides a pivotal attachment of the lever with the cylinder with the ledge between the two portions supporting the lever, and allows the lever to rotate without interference in the horizontal plane. The hole through the inner portion of the lever extension is arranged to grip the cross-section of either square of flat metal stock to be twisted which extends through the hole. This permits the lever to engage and twist stock extending through the lever extension.
The clamp is arranged to grip the pedestal, and is adjustable to permit installing or removing the clamp. The clamp has an opening identical to that through the lever arranged such that the stock extending downward past the clamp has its cross-section gripped by the clamp.
The bottom locator consists of a rod with a perpendicular xe2x80x9cfootxe2x80x9d extension from one end of the rod. The rod is slideably attached to the clamp parallel to the pedestal and can be locked in any desired location to permit locating the bottom locator""s xe2x80x9cfootxe2x80x9d extension extending underneath and supporting the stock.
With the above arrangements, the stock is oriented vertically and located within the hole in the lever, the cylinder and the hole in the clamp, and supported by the bottom locator. With this arrangement, when the lever is rotated horizontally only that portion between the lever and the clamp is twisted, since only these parts grip the stock by its cross-section. The spacing of the lever and the clamp determines the twisted portion length, and the location of the bottom locator determines its location, The location of the clamp on the pedestal also determines the location of the range of adjustments that the bottom locator can provide.
As described above, all of the twister parts which include only a lever, a clamp and a bottom locator are easy to attach and detach from the adaptor and pedestal. If desired, the clamp and bottom locator can even be removed and attached as a unit. While removing the slide bar was indicated as being readily removable in the above description, this bar does not extend far enough to interfere with the twisting operation. Therefore at the option of the operator, the slide bar can be left in place during the twister operation and the other movable bender parts, including the slide lock be detached from the adaptor, since under some conditions the slide lock could interfere with the twister operation. This substitution of the parts required for the alternate bending and twisting operations eliminates any possibility of interaction between them.